Macroscopic vs. microscopic identification of the maturity stages of female horse mackerel

Abstract

Costa, A. M. 2009. Macroscopic vs. microscopic identification of the maturity stages of female horse mackerel. – ICES Journal of Marine Science, 66: 509–516. The consequences to fisheries management of erroneous macroscopic identification of maturity stages are evaluated. The percentage error in macroscopic identification of maturity stages of female horse mackerel (Trachurus trachurus) from the Portuguese coast was determined and analysed by maturity stage, between the periods January–June and July–December, between research surveys and commercial landings, and between per year and month and by length class, to assess its implications in determination of spawning season, maturity ogives, and spawning-stock biomass. The highest percentage errors in macroscopic identification were between late ripening and partly spent stages, in fish >30 cm, and for all fish collected in 1998 and 2005. Late ripening was generally macroscopically underestimated, and the partly spent stage overestimated. The implications for the information provided to the ICES assessment working group are analysed.

Oocytes development, maturity classification, maturity size and spawning season of the red mullet (Mullus barbatus barbatus Linnaeus, 1758)

“…However, classifying individuals based on the method of visual examination of gonads has important limitations. The stage of oocyte development cannot be examined (needed to distinguish sexually active from sexually inactive females), the number of oocytes ready to be released remains unknown, and the presence of postovulatory follicles or atretic stages cannot be assessed (Costa, ; Núñez and Duponchelle, ). These limitations could hinder development of an effective management scheme, especially for multiple‐spawning species, because the incorrect classification of maturity can lead to crucial over‐ or underestimations of fundamental reproductive parameters (Costa, ; Núñez and Duponchelle, ).…”

“…The stage of oocyte development cannot be examined (needed to distinguish sexually active from sexually inactive females), the number of oocytes ready to be released remains unknown, and the presence of postovulatory follicles or atretic stages cannot be assessed (Costa, ; Núñez and Duponchelle, ). These limitations could hinder development of an effective management scheme, especially for multiple‐spawning species, because the incorrect classification of maturity can lead to crucial over‐ or underestimations of fundamental reproductive parameters (Costa, ; Núñez and Duponchelle, ). Several studies reveal discrepancies between the macroscopic and histological examination of the gonads and emphasise the lack of accuracy using macroscopic inspection (García‐Díaz et al., ; La Mesa et al., ; Vacchi et al., ; Costa, ; McBride et al., ).…”

Success and failure assessing gonad maturity in sequentially hermaphroditic fishes: comparisons between macroscopic and microscopic methods

“…*1, This study; 2, Bariche et al (); 3, Burchard et al (); 4, Claereboudt et al (); 5, Costa (); 6, Demartini & Fountain (); 7, Ferreri et al (); 8, García‐Díaz et al (); 9, Hunter et al (); 10, McBride et al (); 11, McPherson et al (); 12, Midway & Scharf (); 13, Smith & Walker (); 14, Stahl & Kruse (); 15, Tomkiewicz et al (); 16, Vitale et al (); 17, Williams (2007).…”

Reproductive phase determination in male meagre (<em>Argyrosomus regius</em>, Sciaenidae): testis development and histologic corroboration of a gross anatomical scale

“…These comparisons considered the histological classification to represent the "truth" because histology is widely regarded as the most accurate staging method for fish gonads (Hunter and Maciewicz 2003, Costa 2009, Ferreri et al 2009). …”